Prepare VM for Container Runtime
https://kubernetes.io/docs/setup/production-environment/container-runtimes/

# run on all nodes

cat <


<strong>Install containerd</strong>
https://github.com/containerd/containerd/blob/main/docs/getting-started.md
https://docs.docker.com/engine/install/ubuntu/#install-using-the-repository
<code>
# run on all nodes

# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl gnupg
sudo install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
sudo chmod a+r /etc/apt/keyrings/docker.gpg

# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
     sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

sudo apt-get update

# Install containerd
sudo apt-get install -y containerd.io

# Verify
systemctl status containerd.service

Configure systemd cgroup driver
https://kubernetes.io/docs/setup/production-environment/container-runtimes/#cgroup-drivers
https://kubernetes.io/docs/setup/production-environment/container-runtimes/#containerd-systemd

# run on all nodes

containerd config default | sudo tee /etc/containerd/config.toml
sudo sed -i 's/SystemdCgroup \= false/SystemdCgroup \= true/g' /etc/containerd/config.toml
sudo systemctl restart containerd

# Verify
# crictl ps -a

Installing kubeadm, kubelet and kubectl
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/#installing-kubeadm-kubelet-and-kubectl

# run on all nodes

sudo apt-get install -y apt-transport-https ca-certificates curl gpg

curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.30/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg

echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.30/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

Initializing your control-plane node
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#initializing-your-control-plane-node

# run on master node

#K8S_MASTER_1_IP=$(hostname -I)
sudo kubeadm init --pod-network-cidr=10.244.0.0/16
#--apiserver-advertise-address=${K8S_MASTER_1_IP}

# install metic server
kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml

Configure k8s configure client
https://kubernetes.io/docs/reference/kubectl/cheatsheet/

# run on master node

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

# export KUBECONFIG=~/.kube/config

# deploy bash completion
kubectl completion bash | sudo tee /etc/bash_completion.d/kubectl

echo "alias k=kubectl" >> .bashrc 
echo "complete -o default -F __start_kubectl k" >> .bashrc 

# verify
kubectl get pod --all-namespaces

Install network addon
https://www.weave.works/docs/net/latest/kubernetes/kube-addon/
https://www.weave.works/docs/net/latest/kubernetes/kube-addon/#-installation

# run on master node

wget https://github.com/weaveworks/weave/releases/download/v2.8.1/weave-daemonset-k8s.yaml -qO /tmp/weave-daemonset-k8s.yaml

# todo: automate
#kubectl edit -n kube-system ds weave-net
vi /tmp/weave-daemonset-k8s.yaml
   ...
    spec:
      containers:
        env:
        - name: IPALLOC_RANGE
          value: 10.244.0.0/16


kubectl apply -f /tmp/weave-daemonset-k8s.yaml

# todo: fix crashed containers
# sudo reboot

# verify
kubectl get all --all-namespaces

Join worker nodes

# run on worker node

# get jon command on master
kubeadm token create --print-join-command

# get join command from the sudo kubeadm init command output
sudo kubeadm join 10.0.10.76:6443 --token ******** \
	--discovery-token-ca-cert-hash sha256:********

# Verify
kubectl get nodes

Deploy test application

# run on master node

# verify
kubectl create deployment nginx --image nginx --replicas 2
#kubectl expose deployment nginx --name nginx-service --type NodePort --port 80

kubectl expose deployment nginx --type=LoadBalancer --name=nginx --port=80

kubectl get all
#APP_PORT=$(kubectl get service nginx-service -o jsonpath='{.spec.ports[*].nodePort}');
#curl 127.0.0.1:${APP_PORT}

kubectl delete deployment nginx
kubectl delete service nginx-service